Ignition system for internal-combustion engines



IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED sEPT.2I. Ien.

1,434,789. E Patented Nov. v7, 1922.

2 SHEETS-SHEET l.

I. H. MELVIN. IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES. APPLICATION FILED SEPT. 21, 1911.

1,434,789. Patented Nov. 7, 1922.

IIIII.I

"III I, II a f3 I I Il@ 5 Patented Nov, 7, 1922.

UNITED STATES PATENT OFFICE.

JOHN H. HELVIN, OF COLUMBUS, OHIO, ASSIGNOB OF ONE-HALF T0 E. B. DILLON, 0F

CLEVELAND, QHIO.

IGNITION SYSTEM: FOR INTERNAL-COMBUSTION ENGINES.

Application led September 21, 1917. Serial No. 192,481.

To all whom it may concern.'

Be it known that I, JOHN H. MELvIN, a citizen of the United States, residing at Columbus, in the county of Franklin and State of (Dhio, have invented a certain new and useful Improvement in Ignition Systems for Internal-Combustion Engines, of which the following is a full, clear, and exact description, reference being had to the 'accompanying drawings.

This invention relates to ignition systems for internal combustion engines, and'more particularly to the so-called open circuit variety, although certain of its features are of broader adaptability. It has to do especially with a self-contained organism, commonly known as an igniter, and comprisin essentially an induction coil, distributlng mechanism, and timing mechanism.

The invention has for its general objects the. attainment of maximum efficiency; compactness, lightness, and comparative simvplicity of structure; economical and speedy production; t accessibility toy all working parts while 1n operation; and consequential ease of inspection, adjustment and repair, in devices of the aforesaid character. Further and more specific objects comprehended by the invention are the production of an ignition system involving a circuit closer which is automatically rendered effective by the starting of the engine, but which normally maintains the circuit open when'the engine is at rest or is inadvertently reversed, thus insuring against back fire, and unnecessary consumption of current should the engine be stopped with the contacts of the igniter engaged; the production of an igniter involving a novel and efficient automatic spark advancer that is positive of operation and is not liable to get out of order; and the production of a device of the aforesaid character wherein the contact points are thoroughly accessible, affording ease of inspection and adjustment, and an opportunity to refinish them when occasion requires.

My improved construction greatly simplifies the usual wiring of ignition systems, requiring but one wire connection in addition to the individual leads tothe spark plugs of the engine. A condenser is employed for intensifying the current, and this condenser and the induction coil are arranged in close proximity to the contacts so that the maximum benefit is derived from the coil and condenser, thus permitting a comparatively small coil to be employed with highly satisfactory results. The period of saturation, being proportionate to the size of the coil, is thus diminished and the electrical lag minimized. Also I employ a cam of greater radius than is usual in instruments of this character, thereby relatively increasing lts peripheral speed with the result that the contacts are very quickly engaged and disengaged, thus minimizin the mechanical lag. Besides the foregoing, there is this other advantage, that the simplicity of construction and accessibility of parts enables any one at all familiar with devices of this character and possessing the knowledge of the average automobile user to test, adjust and repair the device, a privilege not afforded by any of the systems at present on the market with which I am familiar.

The accompanying drawing illustrates a construct-ion involving the foregoing features' and wherein the above objects are arranged, and while I shall proceed to describe it in detail, I wish to be understood as not limiting myself tothe structural details further than is required by the terms of the annexed claims.

Fig. l is a perspective view of the igniter:

Fig. 2 is a central vertical section through the igniter and includes a diagrammatic representation of the ignition system;

Fig. 3Ais a horizontal section on the line 3--3 of Fig. 2, looking in the direction of the arrows;

Fig. 4 is a tributor arm;

Fig. 5, a perspective view of the spring contact finger;

gig. 6, asimilar view of the contact standar Fig. 7 is a bottom plan View of the cam and governor in normal condition:

Fig. 8 is asimilar view of the parts with the governor weights slightly extended; and

Fig. 9 illustrates a modification of the primary circuit.

Describing the invention by the use of reference characters, similar ones of which are applied to corresponding parts throughout the several views, 1 represents the casing, preferably composed of a light weight insulating material, and within the wall of which is permanently contained as by being cast therein the battery wire connection 2, shown as located in the center of the head, and connections 3 for the leads to the various spark plugs. Conductors 4 leadf'rom the connections 3 down through the vertical wall of the casing and merge into the interior of the enlarged lower portion thereof where they are spaced equidlstant about the casing, as most clearly revealed in Fig. 3. The enlarged lower portion of the casing is di vided'from the upper portion by a'horizon# tal partition 5. of insulating material having a central contact plug 6. y

An induction coil `(conventionally illus.- trated in Fig. 2) is housed within the compartment above the partition 5, and one end of its primary winding 10 is attached to the connection 2 while the opposite end thereof leads, through the wire 12, to a vibrator 13. The vibrator, in turn, has connection with a spring contact finger 14, attached bya screw 15 to the outer face of a boss 16 of the casing directly above an opening '17 through which the bumper 18 of the spring finger 'projects' into thev interior of the casing.

his bumper is preferably of insulating material, and may have its inner facel pro tected by a metal cap 19." `As shown clearly' in Figs. 2 and 5, the spring fin er 14 has attached to it a tongue 20'of resi ient material which carries the contact point 21. The

lower end of the finger 14 is turned up andW over `the adjacent end of the tongue to limit the separation of the tongue and finger, thus affording them .a definite normal relation. One end of the' secondary winding 22 of the induction coil'has connection with the contact plug 6, while its` other end isled to a conductor 23 embedded i'n the wall of the casingI and which descends to theextr'eme lower edge thereof'wh'ere it contacts with the' periphery of a supporting plate 24 whereo'n the 'casing is mounted. A condenser 25, shown' as located directly beneath the coil, has 'one of `its sides connected through wire '.26 and screw 15,'Y with the ycontact spring'14, while its other side is grounded through lwire 27 and eonductor 23. main portion "of 'the plate I24 is circular' and fits within the lower end 'of the casing and is providedvwith 'an offset 28 whichprojects beyondfthe 'opening`1 7.' Ajbo's's 29 depends centrally' from thebody portion 'of the supporting plate, andwithin a bore of the bos's and plate is journaled'a shaft 30 having connection with a'driven parti of the engine, suchials 'the'c'ami shaft. Thismay follow the usual 'practice and: therefore 'need not be 'llusta'ted yThefigniter may be supported Irorf the Yengine i"casing 'through a bracket haviii'g" a tubular boss 3,4at its cuter end forf heireception of tlrevboss 295' '1 1"" 'abovejf' th'e'supporting4 plate The 24, the shaft 30 is provided with a collar 35, and journaled upon the shaft above this collar is a' cam disk 36. Spaced equidistant apart about the periphery of the disk are the cams proper 38 (see Fig. 3). The cam disk is preferably dished and contains two substantially semi -circular elements 40. Each element has one of its ends pivoted upon a pin 41 which depends from the disk 36, and its opposite end is connected, by a link 42, to a pin 43, rising from the collar 35. The elements 40 are normally retained in substantially concentric relation with the shaft by light leaf springs 44 which bear against the elements and have rigid connection at one end with the peripheral flange of the disk. Heavier 'springs45 are likewise connected to the .disk and extend out over and are normally spaced slightly from the light springs 44. The mechanism thus constituted, has a peculiar initial action resulting from its link connections. When the' shaft starts rotating in normal direction, as indicated by the arrows in Figs. 7 and 8, its motion is transmitted through the links 42 and elements 40 to the cam disk 36, and the inertia of the disk causes an appreciable rely ative movement between the shaft and disk before the disk attains full speed. This results in the elements being instantly extended. Now, reversely, when the shaft is rotated in the opposite direction, as when the engine back fires7 the elements are held .inward by the inertia of the disk. The light springs 44 readily yield to the'incipient spreading of the elements, so that as soon as the engine is started by cranking or otherwise, a denite relation between the cam disk and shaft 30 is established which may be regarded normal, or the starting point, so to speak. From here on the heavier springs 45 mainly resist the expansion of the elements and gradually yield las the speed increases to allow the disk to advance about the shaft. This provides the automatic spark advance, as w1ll be readily understood. It will bepresently explained how the initial spreading of the elements 40 closes the primary circuit.

A standard 48, of conductive material is supportedv by, and insulated from, the offset 28 ofthe plate 24 beyond the opening 17 andi carries an adjustable' contact oint 49, screw threaded through the stan ard and sustained thereby in operative relation 'to the contact ,point 21, the contact point 49 being held in'any adjusted position by the set screw 50. A contact spring 51 1s secured tothe standard and projects inward' beneath the cam disk where it is shown as providedwith a'bfer' shoe 52. The inner end of thejslioe is inclined downwardlyv and inwardlyfand'is arranged to be engagedand over-,ridden by' the' governor weights 40 las they'are''thrilst outward by the vinitial rotation of the shaft 30 thereby to depress the contact spring into contact with the supporting plate 24.

A distributor arm 55 is fitted into the upper end of the shaft 3() in such manner as to hold it against rotation with respect to the shaft, and this arm is preferably mainly of insulating material. To the upper surface of the arm 1s secured a metallic contact plate 56, having a segmental portion 57, substantially concentric with its axis of rotation, and a tongue 58, equipped with a hardened ball 59 that is held in engagement with the contact plug 6 through the resiliency of the tongue. The edge of the segmental portion 57v of the contact plate 56 travels sufficiently close to the exposed lower ends of the conductors 4 to establish an electric circuit, While affordingno physical contact and thereby obviating wear.-

A readily removable dust cap 60 fits down over the boss 16 of the casingand snugly' about the offset 28 of the supporting plate. The cap may be held in place by any'suitable means, as a screw 61 that passes through an ear of the cap and is threaded into a projection of the offset. I have shown the vibrator 13 as supported by the cap, and the Wires leading thereto may be long enough to allow the removal of the cap without requiring the electrical connections to be disturbed.

The igniter is adapted for use with either battery or magneto circuits, and may or may not incorporate the vibrator 13,.as occasion demands. When employed in connection with such magneto installations as that used on the Ford automobile, a vibrator is essential, and the length of the cams 38 might advantageously be increased in such instances over that prevailing under other circumstances. The vibrator produces a flow of sparks each time the contact points are engaged through the action of the cam, and the increased cam` length prolongs such flow. However in battery circuits I may omit the vibrator and adopt the arrangement illustrated in Fig. 9 Where the wire 12 is shown as leading directly to the spring contact finger 14. I

Referring now to the diagram of Fig. 2 for a description of the circuits, a wire a leads from one side of the source B of electric energy, indicated as a battery, to the connection 2, while the other side of such source is grounded through the Wire a4 to the engine casing. Assuming that the engine is running and the shaft 30 rotating, the elements 40 Will be, extended to depress the contact spring 51 and the cams 38 will intermittentl engage the contact points 21 and 49. Undbr such conditions, current will flow from the source' B, through wire 0.,

primary winding of the coil, wire 12, vi-

brator, contact points, and spring 51 to the supporting plate through which it is ground ed, thus complet-ing the primary circuit. In the meantime the distributor arm is rotating to present the plate 56 into operative relation to the various conductors 4 so that current may flow from the secondary winding 22 of the induction coil through the contact plug 6, plate 56, conductors 4, and wires a2 to the spark plugs P (one being shown in the drawings). The spark plug is grounded to the engine casing, as usual, permitting the secondary circuit to be completed through the bracket 33, supporting plate 24, and conductor 23.

A manually operated switch 62 may be employed for opening the battery circuit to stop theengine; and since the switch comprising the Contact spring 5l automatically opens the primary circuit when the engine is not operating, the switch 62 may be of a push button type, including a spring tending to maintain the circuit closed and opened by pressure upon the button.

I have shown the casing removably secured to the supporting plate or element 24 by spring clips or ngers 63, pivoted at 64 to the plate or element and turned inward at their upper ends into notches 65 of the casing. This constitutes a very simple means of connection, one that is convenient of manipulation, and the resiliency of the clips or fingers insures the parts being held firmly together at all times.

A manual spark control is provided by connecting the usual spark lever to the supporting late 2'4 through mechanism comprising t e rod 66 and ball-joint 67, so that the plate and parts carried thereby, including the bumper 18, may be adjusted angularly of the shaft and cam disk.

By simply removing the dust cap 60, all working parts of the igniter will be plainly revealed and may be inspected while in operation, the opening 17 of the casing affording also a view of the distributer mechanism. The contact point 49 may be adjusted with great ease, and should it be found necessary, the faces of the contact points may be dressed off or refinished, as with a file or other instrument.

Having thus described my invention, what I claim is 1. In a system of the character set forth, the combination of an induction coil; a pair of contact points; a source of electric energy; a circuit including said source, the primary winding of the coil, and said contact points; distributor mechanism; a circuit including the secondary winding of the coil, and said mechanism; a shaft; means for drivingthe shaft; a cam for effecting intermittent engagement of the contact points; and driving connections between the shaft and cam and through which the cam is advanced angularly Vof the shaft only when the shaft is rotated in normal direction. l

. 2. In a system of the character set forth, the combination of an induction coil; a pair of contact points; a source of electric energy; a circuit including said source, the primary windingv of the coil, and said contact points; distributor mechanism; a circuit including the secondary winding of the coil, and said mechanism; a shaft; means for driving the shaft; a cam for effecting intermittent engagement of the contact points; and link connections between the shaft and cam whereby the camis advanced angularly with respect to the shaft only when the shaft is rotated in normal direction.

3. In a device of the character set forth, the combination of a casing having an open end and an opening in its side adjacent said end, an induction coil contained within the opposite end of the casing, distributor-points arranged about the interior of the casing, an element closing the open end of the casing, a shaft journaled within a borey of said element and projecting into the casing central of the aforesaid distributor points, a distributor arm operatively connected to the shaft and adapted to be moved thereby into operative relation to said points, said arm carrying a contact member in circuit with the secondary windingof the induction coil, a cam situated below the distributor arm and operatively connected to the shaft, a movable contact member exterior of and supported by the casing and having a part projecting through the side opening for engage ment with the cam, and a second contact member sustained in operative relation to the first contact member, said contact members being in circuit with the primary windf ing of the induction coil.

4. In a device of the character set forth, the combination ofA a vertical casing of insulating material havin connections exposed through the top thereo and conductors leading from said connections downward into the lower portion of the casing to constitute distributor points, an induction'coil within the upper portion of said casing, a condenser next below said induction coil, a partition closing thel portion of the caslng occupied by the coil and condenser and having a central contact plug, an element closing the lower end of the casing, a shaft journaled within said element and projecting into the casing, a distributor arm operatively connected to the shaft and having a contact bearing upon the aforesaid contact plug, the arm being arranged to travel in operative relation to the aforesaid distributor points, a cam situated below the distributor arm and operatively connected to the shaft, a

pair of conta/ct members exterior of the casing, one of said members being carried by the casing and the other by the'aforesaid element, the casing having an opening through which the cam may effect engagement of said contact members, a terminal within the upper end of the casing in circuit with the primary winding of the coil and one of said contact members, and a conductor carried by the casing and arranged for engagement with the aforesaid element when the casing is applied thereto and having electrical connection with one end of the secondary winding of the coil. the other end of the secondary winding being in connection with the aforesaid contact plug.

5. In timing mechanism of the character set forth, the combination of a pair of contact members, normally separated switch elements, a circuit includingsaid contact members and switch elements, an operatin shaft, a cam having driving connection wlth the shaft and arranged to effect engagement of the contact members, and means movable by and radially of the shaft when the same is rotated to override one of the aforesaid switch elements and move it into contact with the other.

6. In mechanism of the character set forth, the combination of a shaft, a cam disk journaled thereon, an element having one of its ends pivotally connected t-o the disk, a link having one of its ends likewise connected to the shaft eccentric thereof, and means pivotally connecting the free ends of the link and element. i

7. In mechanism of the character set forth, the combination of a shaft, a cam disk journaled thereon, a pair of elements each having one of its ends pivotally connected to.

the disk at a point substantially diametrically opposite the pivotal connection ofvl the other, and a pair of links each having one of its ends pivotally connected to the free end of one of the elements and its opposite end likewise connected to the shaft eccentric thereof;

8. In mechanism of ythe character set forth, the combination of a shaft, a cam journaled thereon, a plurality of elements each having one of its ends pivotally connected to the cam, a plurality of links each having one of its ends pivotally connected to the-free end of one element and its opposite e'nd likewise connected to the shaft eccentric thereof so that as the shaft rotates in a given direction it will effect an outward movement of the elements, a pair of contact members arranged to be engaged through the instrumentality of the cam, and means yieldingly retaining the elements in normal position.

9. In mechanism of the character set i nected to the cam, a plurality of links each having one of its ends pivotally connected to the free end of one element and its op site end likewise connected to the shaft eccentric thereof so that as the shaft rotates in a given direction it will effect an outward movement of the elements, a pair of contact members arranged to be engaged through the instrumentality of the cam, a switch arranged to be operated by the initial outward movement of the elements, means tendin to retain the elements in normal positionwilo yielding to the initial outward movement thereof, and auxiliary means yieldingl resisting further outward movement ofY the elements.

10. In mechanism of the character Set fortl, the combination of a shaft, a cam journaled thereon, driving connections between the shaft and cam of a nature permit- 20 y ting relative angular movement therebetween as the shaft is rotated, said connections involving elements that are moved substantially radially as the shaft is rotated in a. given direction, a pair of contact members arranged to be engaged through the instrumentality of the cam, a switch arranged to be operated by the initial radial movement of said elements in one direction, means tending to retain said elements in normal position while yielding to such initial movement, and auxiliary means yieldingly resisting further movement of the elements in the same direction.

In testimony whereof, I hereunto aiix my signature.

JOHN H. MELVIN. 

